A　novel　aptamer-functionalized　metal-organic　framework　nanofibrous　composite　(viz.　PAN/UiO@UiO(2)-N-3-aptamer)　with　a　high　aptamer　coverage　density　was　proposed　based　on　the　electrospinning　and　seeded　growth　method,　and　used　for　specific　affinity　recognition　of　trace　Microcystin-LR　(MC-LR).　Heterobifunctional　ligand　was　used　to　modify　the　metal-organic　framework　nanoparticles　(MOF　NPs)　surface,　which　could　passivate　the　MOF　surface　with　respect　to　unmodified　DNA,　followed　by　coupling　massive　aptamers　on　MOF　of　the　solid-phase　microextraction　(SPME)　fiber　using　click　chemistry.　Characterizations　including　morphology,　spectra　analysis,　mechanical　stability,　binding　capacity　and　specificity　were　fulfilled.　Applied　to　the　analysis　of　MC-LR,　the　good　selective　and　sensitive　recognition　were　obtained　with　the　detection　limit　as　low　as　0.003　ng/mL,　which　was　better　than　most　non-specific　SPME　or　solid-phase　extraction　(SPE)　protocols.　The　stability　and　reproducibility　were　acceptable,　and　the　intra-day,　inter-day　and　column-to-column　relative　standard　deviations　(RSDs)　for　the　recovery　of　MC-LR　were　gained　in　the　range　from　2.5%　to　14.3%,　respectively.　Satisfactory　recoveries　of　MC-LR　in　environmental　water　samples　were　measured　as　96.3　+/-　4.7%　-　98.9　+/-　2.7%　(n　=　3)　in　tap　water,　94.4　+/-　2.5%　96.1　+/-　3.5%　(n　=　3)　in　pond　water,　and　97.0　+/-　2.1%　-　97.9　+/-　3.1%　(n　=　3)　in　river　water,　respectively.　This　work　demonstrated　that　the　electrospun　nanofibrous　composite　with　massive　aptamers　would　be　a　better　alternative　for　ultra-trace　MC-LR　detection　with　good　selectivity,　matrix-resistance　ability　and　high　resolution.